There is an ever-increasing need for efficiency in producing animal protein for human consumption. As world population continues to increase, available animal feed materials increase in price, and it becomes most important that maximum growth potential from available feed materials be realized.
In monogastric food-producing animals such as swine and poultry, feed additives may be employed to protect against subclinical gastrointestinal infections, and thereby enable the target animal to realize its greatest food-producing potential. When such animals receive such feed additives on a daily basis at low levels, greater control of parasitic infections, such as coccidiosis, can be realized, and more of the feed goes to growth.
In ruminant animals such as cattle, goats and sheep, significant improvements in feed efficiency and growth can be obtained by chemical modification of the metabolism of rumen microorganisms. This may be accomplished by reducing the proportion of methane formed, and increasing the proportion of propionate at the expense of methane and acetate. Methane tends to be formed during fermentation of food in the ruminant. This represents a loss in feed energy intake, because the methane gas is lost by eructation.
Propionic acid is a much more efficient precursor of glucose, from which the animal derives its energy and growth, than acetic acid. It is, therefore, most desirable to shift the balance of rumen metabolism toward propionate production to obtain more efficient feed utilization and to promote growth in ruminants.